Widespread screening for newborn hearing loss has become routine in many countries over the past decade. Writing in the New England Journal of Medicine [May 18th], William Nance of Virginia Commonwealth University says the spread of such programs throughout the world has produced a revolution in health care. "The whole premise behind newborn hearing screening is that there is a critical period during the development of an infant when, if they do not develop language, they will never be able to develop it to their full potential."

Despite its success, screening could be improved, Nance writes. He calls for quicker results, better recognition of infants at risk for delayed onset of hearing loss, more focus on the causes of hearing loss and a new battery of genetic tests. "The molecular tests on newborn blood spots would identify the most common genetic cause of deafness at birth, the most common genetic cause of late onset hearing loss, the most common environmental cause for hearing loss at birth and later in infancy, and the most common preventable form of hearing loss."

For example, Nance says, a genetic test could detect an extreme sensitivity to a common antibiotic used in newborns that in rare instances can cause deafness. "If you simply identify individuals who have this gene for sensitivity and don't give them this antibiotic, you can prevent them from ever being deaf in the first place."

Nance says 50 to 60 percent of childhood hearing loss in developed countries is due to genetic factors. He says detecting the problem early and making accommodations for it can improve success in school and in life.